Structural Description:

Coating the buried pipeline is of great importance for the life of the same material pipelines, some buried in the ground for decades without corrosion, leakage occurred some years. It is because they are different from the coating. Polyethylene protective layer known as the three-tier structure of the three-tier PE, in the last few years from the introduction of advanced foreign anti-corrosion technology. It's called Fusion bonded epoxy / protective layer extruded polyethylene structure, the three-tier structure of the following components: Fusion bonded epoxy to the bottom (60-80 μ M) for the adhesive layer (170-250 μ M) Surface Extrusion for polyethylene (about 2 mm). Protective layer thickness greater than 2.2-2.9 mm.

In the three-tier structure, epoxy primer's main role is: A continuous coating and pipe bonded directly from the surface, has good chemical resistance and anti-corrosion properties of the cathode stripping with the middle layer of adhesive response group a chemical bond to ensure that the overall coating at the higher temperatures have good adhesion. The middle layer is usually copolymer binder, and its main ingredient is polyolefins, is now widely used vinyl copolymer adhesive. Copolymer adhesive polar functional groups of epoxy primer and epoxy groups can be the reaction of hydrogen bonds or bond so that the intermediate layer and the bottom to form a good bond; Not part of the polarity of ethylene and polyethylene surface a good PRO-cooperation, and therefore the middle layer and the surface also has very good adhesive properties. Polyethylene surface is the primary role of a mechanical protection and preservation, two-story structure with the traditional polyethylene coating has the same effect. The three-tier structure of polyethylene coating integrated epoxy coating and two polyethylene extrusion coating the fine nature, will be epoxy coating interface characteristics and chemical resistance characteristics, and the extrusion of polyethylene coating Mechanical features combined with the advantages, thereby significantly improve their performance. Buried pipelines as a result of the protective layer is very excellent. According to relevant data, the three-tier PE buried pipeline will reach the life span of 50, at present, it has to be considered to be the most advanced anti-corrosion technology, pipeline. In China, PE has taken the lead in the three-tier oil and gas system applications. China has completed the Shaanxi-Beijing natural gas pipeline and the pipeline Shan, the recent national key project to build a 4, 000 km pipeline near adopted a three-PE, anti-corrosion coating. In Tianjin, Shanxi-gas into high-pressure pipeline 67 km, 30 km, NOL high pressure natural gas pipelines, Shaanxi-Beijing line underground gas storage is a 122 km pipeline tier PE. It has become a pipeline of the future direction of development of anti-corrosion layer.